Stir together a half cup of the salsa verde with one cup of chicken broth and the diced tomato in your slow cooker. Add the chicken breasts and spoon the salsa-broth mixture over the chicken. Cover and set on low.
Cook for 4 to 6 hours until chicken is cooked through and shreds easily.
Transfer the chicken from the slow cooker to a cutting board. Use two forks to shred the chicken.
Preheat oven to 400° F. Add one to two tablespoons of salsa to the bottom of a small casserole dish.
Scoop a quarter of the chicken into one flour tortilla and roll it lengthwise until it forms an enchilada shape. Place inside the prepared casserole dish and repeat for the remaining chicken and tortillas.
Evenly pour the remaining salsa over the enchiladas, and then cover with the cheese.
Bake on the center rack for 20 minutes or until the enchiladas are golden-brown.
Remove from oven and garnish with fresh cilantro and chopped green onion. Serve and enjoy.